Lots of studies on gold precipitation mechanisms have focused on fluid inclusions within quartz. However, the trace elements in quartz reflect the properties of the ore fluid, and a comparison of the trace element content in different types of quartz can reveal the precipitation mechanism. The Jinqingding gold deposit is the largest gold deposit in the Muping–Rushan gold belt and contains the largest single sulfide–quartz vein type orebody in the gold belt. This study distinguished four types of quartz in this orebody through field work and investigations of the mineralogy and cathodoluminescence (CL) of the quartz and crosscutting relationships as seen under a microscope. In situ studies via electron probe micro-analyzer (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) were used to determine the trace element content of the different quartz types. Type Qa displayed a comb structure in the field and zoning under the microscope and in CL. Milky white and smoke grey Qb was the most common quartz type and hosted the most sulfide and gold. Qc was Qa and Qb quartz that recrystallized around pyrite or overgrew and appeared different from Qa and Qb in CL images. Qd occurred within fractures in pyrite. Qa formed prior to the mineralization of gold, and Qd formed post-mineralization. Qb and Qc provided information regarding the ore fluid during mineralization. Sericites occurred with pyrite in fractures in the quartz, and some, along with free gold, filled in fractures in pyrite. Free gold occurred within Qa, Qb, Qc, and in brittle fractures in pyrite. Qc had the lowest Al content of all of the quartz types. As Al content is related to the acidity of the ore fluid in previous study, this indicated an acidity decrease during mineralization, which could be attributed to the sericitization. Sericitization could indicate a potential gold occurrence. The Ti content decreased from Qb to Qc, indicating a decrease in temperature during quartz overgrowth formation. Change in acidity and cooling can therefore be identified as possible causes of gold precipitation in the sulfide–quartz vein type in the Jinqingding gold deposit.

Controversy surrounds the genetic relationship between gold mineralization and magmatism, especially in deposits in granite. Jiaodong Peninsula is the leading gold province in China, and most deposits are in Mesozoic granites; moreover, debate on the genesis persists. In eastern Jiaodong, the Muping–Rushan gold belt produces mainly quartz–sulfide vein-type gold, and the Upper Jurassic Kunyushan granite and Late Lower Cretaceous Sanfoshan granite are the wall rock. Precise mineralization ages should be identified to determine whether gold is related to the intrusion. In this study, three gold deposits (Sanjia, Yinggezhuang, and Xipo) from two ore-controlling faults were considered. Muscovites from quartz–sulfide veins and beresite were selected for Argon–Argon dating. The results obtained were 116.51 ± 0.47 Ma, 120.02 ± 0.38 Ma, and 121.65 ± 0.48 Ma for the three deposits, respectively. The mineralization lasted about 5 Ma in the Muping–Rushan gold belt. The test results showed that the mineralization was 16 Ma later than the intrusion time of Kunyushan granite and was earlier than that of Sanfoshan granite. Only the cooling age overlapped with the mineralization age. Previous studies have demonstrated that the ore fluid is of medium–low salinity and medium–low temperature. No typical high–low temperature mineral assemblage exists in the Muping–Rushan gold belt. Hence, gold deposits in Muping–Rushan gold belt could not be categorized as intrusion-related gold type.